A teratogenic study on Original Woo-Whang-Chung-Sim-Won was carried out in SpragueDawley rats. Original Woo-Whang-Chung-Sim-Won suspended in distilled water was administered to pregnant dams by oral gavage during organogenesis period (from 7th to 17th day of gestation) at daily doses of 1/9, 1/3 and I pill/kg. About two-thirds of dams were sacrificed at 20th day of gestation to scrutinize the pregnant performances and fetal development, and the remaining dams were allowed to deliver. The growth, reflex, behaviour and reproductive function of F1 offsprings were examined. There was no treatment-related difference in body weight, food consumption and necropy findings of dams. No gross, skeletal and visceral abnormalities was observed in F1 fetuses from dams treated with Original Woo-Whang-Chung-Sim-Won. F1 offsprings did not show any treatment-related difference in growth, reflex, behaviour and reproductive peuformance. At caesarean section of F1 dams, no growth retardation and gross abnormality was observed in F2 fetuses. In conclusion, Original Woo-Whang-Chung-Sim-Won did not show any potential teratogenic activity in rats.